Hydraulic jarring tool



Nov. 15, 1966 D. E. YOUNG HYDRAULIC JARRING TOOL Filed March ll, 196% I N VENTOR. a MQ 701//0/ f'. young United States Patent O 3,285,353 HYDRAULIC JARRING TOOL David E. Young, Bellaire, Tex., assignor to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Filed Mar. 11, 1964, Ser. No. 351,159 12 Claims. (Cl. 175-297) This invention relates to jars and more particularly to hydraulic jars for use in a well bore.

In the oil industry, jars are used on a wire line or string of drill pipe for the purpose of providing, when needed, an impact force to a part stuck in a well bore. Jars operate on the principle of a hammer member striking an anvil member to deliver a large impact force to the stuck part. A hydraulic jar uses a hydraulically timed delay for the purpose of developing large` forces within `a hydraulic system in the well which, when released, impact the hammer on the anvil generating .a large shock force on the stuck part. The time delay in such a system typically is provided by restricting flow of hydraulic fluids between telescoping members while the hammer member moves toward the anvil member. This restricted Huid flow is dependent upon the size of a restricted orifice formed between the telescoping jar members and therefore, tolerances of the orice are normally very close and are affected by changes in temperature. Additionally, the telescoping members are subjected to very high pressures developed 'within the jar.

Accordingly, it is an object of the present invention to provide la jar having a hydraulic time delay which is not temperature sensitive.

Another object of the present invention is to provide a jar wherein the hydraulic delay mechanism is not subjected to the load applied and high pressures generated between the impacting members.

Yet another object of this invention is to provide a jar having a hydraulic time delay system not dependent on critical tolerances between the sliding elements of the system.

With theseV and other objects in view, the present invention contemplates an apparatus having telescoping members adapted for coupling in a string of pipe and a hydraulic delay system formed within the members for developing a large releasable force between the members. More particularly, the` apparatus includes a tubular housing member formed laround an upper and lower tubular mandrel assembly. The upper mandrel is connected to the string of pipe depending in the well bore and the lower mandrel is connected to a section of pipe which has become stuck in the well bore. Hydraulic fluid chamber means are formed between the housing and the mandrel members and, by the application of a force on the upper mandrel to move the upper mandrel up and away from the lower mandrel, a large hydraulic pressure is formed in a lower portion of the chamber means. A delay valve mechanism which is positioned in the chamber provides for release of the high fluid pressure in the lower chamber portion into an upper chamber portion after a time delay. This release permits a hammer portion formed on the housing to forcibly strike an anvil formed on the lower mandrel. This striking force applied to the lower mandrel in turn is transmitted to the section of pipe which is stuck in the well bore.

A complete understanding of this invention may be had by reference to the following detailed description when read in conjunction with the accompanying drawings which illustrate an embodiment thereof wherein:

FIGS. 1-3 are vertical sectional views of a well tool embodying the present invention showing various stages of operation of the tool.

Referring to FIG. 1 a hydraulic jar is shown with upper "ice and lower telescopically arranged mandrel portions 12 and 13 respectively having opposite ends threaded for connecting the jar in a string of drill pipe or tool string. The telescoping ends of the mandrel portions 12 and 13 are received within tubular interconnecting housing 27. At the upper end of housing 27, a pair of longitudinally spaced, inwardly extending anges 28, 33 are slidably received on the mandrel portion 12, the ange 33 having an O-ring seal 33a. Between anges 28, 33 the housing 27 has longitudinally extending splines 35 which mesh with short 4length splines 14 on mandrel portion 12 to provide a co-rotative coupling. Thus, spline 14 can be moved longitudinally relative to spline 35 between the ilanges 28, 33. At the lower end of housing 27 an inwardly extending flange 29 is provided with an O-ring seal 32 so as to be slidably and sealingly received on mandrel portion 13. Flange 29 also forms the hammer of the jar and is shown spaced from an outwardly extending flange 37 on mandrel portion 13, the ange 37 forming the anvil of the jar. Longitudinally extending splines 34 and 36 respectively on housing 27 and mandrel portion 13 provide a sliding interconnection. It will be appreciated that housing 27 is spline connected to mandrels 12 and 13 permitting torque or rotational movement to be transmitted by the jar assembly. The lower mandrel portion 13 has an annular sleeve portion 18 telescopically received over the lower end of the upper lmandrel portion 12 and sealed thereon by an O-ring 26, the sleeve portion 18 being sized relative to housing 27 to form an annular chamber 31 between the sleeve portion and the housing. .At the upper end 19 of the sleeve portion 18 is a thin-walled section 19 spaced from the mandrel 12 so as to form a space or annular chamber 19a.

A n outwardly extending `annular ange 21 is formed on the upper end 19 of the sleeve and has a seal ring 22 for sealing sleeve 18 relative to housing 27. A valve port 23 is formed through the wall of the thin-wall portion of the sleeve below the llange 21. A spring biased check valve 24 extends through the sleeve 18 below the thin-wall portion to permit lluid ow from chamber 19a to chamber 31 but preventing iluid ow in an opposite direction. It will be noted that the anges 33 and 29 of housing 27 seal oi portions of eqn-al diameter on mandrel portions 12 and 13. The sleeve portion 18 of mandrel 13 by virtue of seal 22, and seal 32 between the mandrel 13 and housing 27 dene the sealed chamber 31.

The annular space between sleeve portion 18 and upper flange 33 receives an annular delay piston 41. Delay piston 41 has an intermediate portion 43 slidably mounted on mandrel 12 and sealed thereon with an O-ring 46. Piston 41 also has a depending thin-walled section 48 disposed intermediate of mandrel 12 and housing 27 with a close tting but sliding reception within sleeve end 19. A port 47 is formed through thin-walled section 48 to provide a iluid communication path between a space 30 formed below piston 41 and chamber 19a. Port 23, when covered, serves to substantially prevent uid communication between chambers 19a and 31. When section 48 uncovers port 23 by moving upward, iluid may low from chamber 31 to chamber 19a and through port 47 into space 30.

The outer section of piston 41 has longitudinal grooves 51 permitting fluid bypass. At the upper end of grooves 51, piston 41 has a frusto-conical taper valve seat 54 on which an annular complementarily shaped valve member 53 seats. Valve member 53 is normally biased into a seating position on the valve seat 54 by a spring 56 acting between flange 33 and the valve member. It will be appreciated that movement of piston 41 upwardly seats lthe valve member 53 on the valve seat 54. A restricted clearance 57 is made between the valve member 53, and housf ing 27 to leak uid in a metered manner from a space 52 above .the piston around the outside of valve member 53 through the grooves 51 and into the space 30 below the piston. j

The upper end of the piston 41 has an L-shaped, inwardly extending flange or shoulder 44 slidably received on mandrel 12. Shoulder 44 is longitudinally spaced from a flange 17 extending outwardly from the mandrel 12, the piston being slidably Ireceived over flange 17. A time delay spring 45 is positioned between the flange 17 and the piston shoulder 44.

The inner wall of housing 27 is provided with a section 55 having longitudinally extending grooves. When the valve member 53 straddles these grooves (FIG. 3) lluid 'can rapidly bypass the valve member 53 while it is moving upward. A recess 58 is provided between the valve member 53 and piston 41 so that when the piston moves downwardly, fluid can easily bypass the valve member 53.

A spring biased pressure compensating piston 40 is positioned in the flange member 33. Well lluid pressure communicates with the upper end of the compensating piston through a port 28a formed in the upper flange 28.

In the operation of the apparatus shown in FIGS. 1-3, it is to be remembered that the lower mand-rel 13 is connected to the portion of pipe or well tool which is stuck in the well bore. The upper mandrel 12 is connected to a string of pipe or a tension membe-r extending to the surface of the well where tension is applied. Upon applying tension, mandrel 12 moves upwardly and compresses the spring 45 between the flange 44 of the slow moving piston 41 and the shoulder 17 formed on the mandrel as shown in FIG. 2. Subseqently, as the spring 45 becomes fully compressed, the shoulder 14 on the mandrel engages the bottom of the liange 28 formed on the housing (FIG. 2). Upon the further application of an upward force to the upper mandrel 12 of the jar, the

force is transmitted through the shoulder 14 to the inwardly extending flange 28 on the housing. This force, in turn, tends to move the housing 27 upwardly relative to the lower mandrel 13 and apply pressure on the fluids in the lower fluid chamber 31 `formed between the lower mandrel and the housing. This chamber 31 is blocked at its upper end by the sealed shoulder 21 of the lower mandrel engaging the housing. At the same time that the lluids are being pressured in this chamber, the force applied to the upper mandrel from the upward tension on the pipe is transmitted upwardly through the spring 45 to the shoulder portion 44 of the pisto'n. This force of the spring 45 overrides the force of spring 56 to move the piston upwardly in the space 52 formed between the piston 41 and the flange 33. However, the annular sleeve 53 is being forced down upon the top sloping end 54 of the piston by the spring 56 to close off fluid ilow around the large bypass S1. In this condition, fluid flow is only permitted through the restricted clearance 57 formed between the housing wall and the `outer surface o-f the sleeve 53. As fluid flows around or through this restricted portion 57 of the sleeve, the piston slowly moves upwardly in the upper space under the force being applied to the piston through the spring 45 from the upward tension on the mandrel. When the sleeve 53 moves up into a position over the recess. 55 (as shown in FIG. 3), a larger bypass iswalorded for ow of uid around the sleeve and subsequent rapid movement of the sleeve and consequently the piston 41 takes place. As the piston rapidly moves upwardly in the chamber, ythe thin-wall section 48 depending from the lower portion of the piston moves npwa'rdly to uncover the port 23 in the lower mandrel sleeve to permit a dumping of the pressured lluid in the lower chamber 31 through the port 23 into the cham- This sudden v he/pressured fluid from lower chamber 31 x lower inwardly extending flange or hammer 29 'lower face of the anvil 37 formed on the thereby transmitting a sudden force to the ndingto free parts attached to the lower tu 4in the well bore.

:1:19a and, space 30 below the piston.

The jar may be recocked for further use by applying .a downward force on the upper mand-rel 12. When the jar is recocked (see FIG. l), the outwardly extending flange 17 formed on the upper mandrel 12 abuts against the upper end of the intermediate portion 43 of the piston and moves the piston downwardly within the .chamber 19a to close oli the dumping port 23 in the sleeve end 19. During this downward movement the fluid which lhas rushed into the chamber 19a and space 30 during the jarring action passes back through the lower mandrel sleeve 18 through the check valve 24 positioned in the wall of the sleeve and into the pressure chamber 31. This rapid resetting of the jar is further facilitated by a rapid llow of lluid around the piston positioned in the upper annular space because the uid owing from the space 30 upwardly around the piston through the bypass 51 tends to unseat the sleeve 53, normally closing the large bypass 51 around the piston, and permits fluid flow through the large bypass 51, under the sleeve, and up through the enlarged bypass opening 58 between the sleeve and the extending shoulder portion 44 on the piston.

During the operation lof a hydraulic jar, normally the large tensional force which is applied to the jar is transmitted to the delay mechanism and subjects the iluid chamber associated with the delay mechanism to very high pressures. Since the delay `depends on the metering of Huid through a restricted oriice, the high pressure necessitates the use of close tolerance lits in the mechanism. As a result, changes in temperature encountered in the well bore have a profound elect on the `operation of the delay mechanism and tend to render the operation of the delay mechanism unreliable. Additionally, the high pressures cause rapid erosion of the metal surfaces and extrusion of seal members subjected to the pressures.

In the present apparatus, the large tensional force which is applied to the jar to perform the jarring action is not directly transmitted to the delay mechanism. Instead the spring 45 is interposed between the shoulder 17 on the tensioned mandrel and the shoulder 44 on the piston. Therefore, the force applied to the piston is determined by the strength of the spring 45. As a result of this lesser force the tolerances of t between the piston 41, sleeve 53, and housing wall are not as critical as they would be if utilized in a high pressure chamber. Thus, temperature differentials in the well bore do not have the characteristic effect of rendering the delay mechanism unreliable since the dimensional changes in the ports are relatively less signilicant due to the greater tolerances between parts. Maintenance on the tool is also reduced las a result `of the lower pressures to which the delay mechanism is subjected.

It will readily be seen that the above-described apparatus may have other uses in well tools wherein it is desired to transmit a large or sudden force between members of a well tool by the buildup of high pressure in la chamber with subsequent sudden release of the pressure in the chamber to cause a rapid movement between the members. It is also noted that a slightly different arrangement of the ports would provide for down strain jarring on the drill pipe. Additionally, the mandrel and housing sections may be reversed with the present mandrel members being placed on the outside of the tool.

While a particular embodiment of the present invention has been shown and described, it is apparent that these and other changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such uses, changes and modiications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A well jar for use in -a well bore comprising;

telescopically arranged members,

a tubular housing slidably positioned over said telescoping members,

means arranged between said housing and one of said members for releasably holding said housing from substantial longitudinal movement relative to said one member,

means arranged between the other of said members and said housing for transmitting a large upwardly directed force applied to said other member from said other member to said housing, and

means responsive to a much lessor force generated by said large force for releasing said holding means after a time delay to permit relative movement between said housing and said one member.

2. A well tool apparatus for transmitting forces applied to drill pipe, said tool comprising:

-a pair of telescopically arranged members,

a tubular housing slidably positioned over said telescoping members, said members and housing being arranged for connection and suspension from the drill pipe,

means arranged between said housing and one of said members for releasably holding said housing from substantial longitudinal movement relative to said one member.

means arranged between the other of said members and said housing for transmitting a large upwardly directed force applied to the drill pipe and said other member from said other member to said housing, and

means responsive to a much lessor force generated by said large force for releasing said holding means after a time delay to permit relative movement between said housing and said one member,

hammer and anvil means formed on said housing and said one member and positioned to engage one another with impact when relative movement occurs between said housing and said one member.

3. A well tool apparatus for transmitting forces applied to drill pipe, said tool comprising:

a pair of telescopically arranged members,

a tubular housing -slidably positioned over said telescoping members,

means arranged between said housing and one of said members for releasably holding said housing fixed from longitudinal movement relative to said one member,

means arranged between the other of said members and said housing for transmitting a large force applied to the drill pipe and said other member from said other member to said housing, said other member being connected to the drill pipe,

means responsive to said force for releasing said holding means after a time delay to permit relative movement between said housing and said one member, and

means positioned between said other member and said releasing means for reducing the force applied to said releasing means.

4. A well tool apparatus for transmitting forces applied to drill pipe, said tool comprising:

a pair of telscopically arranged members,

a tubular housing slidably positioned over said telescoping members,

fluid means between said housing and one of said members for releasably holding said housing xed from longitudinal movement relative to said one member,

means arranged between the other of said members and said housing for transmitting a large force applied to said other member to said housing, and

means responsive to said iluid force for releasing said holding mean-s after a time delay to permit relative movement between said housing and said one member, and

means positioned between said other member and said releasing means for reducing the force applied to said releasing means,

means on said housing and said one member for engaging one another with impact upon release of said holding means.

5. A hydraulic jar apparatus comprising:

a pair of telescopically yarranged members each having end portions adapted for connection between a stuck part in a well Ibore and a tension app-lying part,

a tubular housing positioned over said telescoping members,

means forming a fluid chamber between said members and said housing,

sealing means on one of said members dividing said chamber into -upper `and lower portions,

said one member having a port formed therein for permitting fluid communication between said upper and .lower chamber portions,

piston means positioned in said upper 4chamber and movable between at least two positi-ons, said piston means having a portion thereon covering said port in said one member when said piston is in one of said positions,

means responsive to a lon-gitudinal force on one of said members for urging said piston to said other position with a force less than the force applied to said membe-r, and

means for delaying the movement of said piston to said other position to uncover said port.

6. A hydraulic jar apparatus comp-rising:

a. pair of telescopically arranged mem-bers each having end portions adapted for connection between a stuck part in a well bore yand a tension applying part,

a tubular housing positioned over said telescoping members,

means forming a fluid chamber between said members and said housing,

sealing means on one of said members dividing said chamber into upper and lower portions,

said one member having a port formed therein for permitting fluid communication between said upper and lower -chamber portions,

pist-on means positioned in said upper chamber and movable between at least two positions, said piston means having a portion thereon covering said port in said one member when said piston is in one of said positions,

means responsive to a longitudinal force on one of said members for urging ,said piston to said other position with a force less than the force .applied to said member,

means for delaying the movement of said piston to said other position to uncover said port, and

hammer and anvil means formed on said housing and said one member .and positioned to engage one another with impact in response to lmovement of said piston to said other position to uncover said port.

7. A hydraulic jar apparatus comprising:

a pair of telescopically arranged members each having end portions adapted for connection between a stuck part in a well :bore and a tension applying Part,

a tubular housing positioned over said telescoping members,

means forming a iluid chamber between said members and said housing,

sealing means on one of said members dividing said 'chamber into upper and lower portions,

said one member having a port formed therein for permitting liuid communication between said upper and lower chamber portions,

piston means positioned in said upper chamber and movable between at least two positions, said piston means having a portion thereon covering said port in said one member when said piston is in one of said positions,

said one member also having a valve positioned therein for permitting fluid ow between said upper and lower chamber in only one direction when said port is covered,

and means responsive to a longitudinal force on one of said members for urging said piston to said other positi-on with a force less than the force applied to said member, and means for delaying the movement of said piston to said other position to uncover said port. 8. A hydraulic jar apparatus comprising: an upper mandrel member slidably received within a lower mandrel member, a housing member slidably positioned over said mandrel members, means forming a fluid chamber between said mandrel members and'said housing member, means extending -from said lower mandrel for dividing said chamber into upper 4and lower portions, means in said extending means for providing a iluid communication port bet-Ween said upper and lower portions, movable piston means positioned in said upper portion, said piston having a depending portion for covering said port, means for transmitting al llarge force applied to said upper mandrel to said housing, means responsive -to a much lesser force for providing a delayed movement of said piston in said upper chamber to uncover saidl port between said upper and lower chamber, said delay means effective to delay the movement of said piston in one direction while permitting rapid movement of said piston in the other direction. 9. A hydraulic jar apparatus comprising: an upper mandrel member slidably received within a lower mandrel member, a housing member slidably positioned over said mandrel members, means forming a fluid chamber between said mandrel members and said housing member, means extending from said lower mandrel for dividing said chamber into upper and lower portions, means in said extending means for providing a fluid communication' port between said upper and lower portions', movable piston means positioned in said upper portion, said piston having a depending portion for covering said port, said extending means also having valve means therein for permitting fluid flow in one direction between said upper and lower portions, means for transmitting a large force applied to said upper mandrel to said housing, means responsive to a much lesser force for providing a delayed movement of said piston in said upper chamber to uncover said port between said upper and lower chamber, said delay means effective to delay the movement of said piston in one direction while permitting rapid movement of said piston in the other direction. 10. A hydraulic jar apparatus comprising: an upper mandrel merrnber slidably received within a lower mandrel member, a housing member slidably positioned over said mandrel members, means forming a fluid chamber between said mandrel members and said housing member, means extending from said lower mandrel for dividing said chamber into upper and lower portions, tmeans in said extending means for providing a fluid communication port between said upper and lower portions,

Vmovable piston means positioned in said upper portion, said piston having a depending portion for covering said port,

,meansv for transmitting a large force applied to said Ppflt'mllldrel -to said housing,

means responsive to said force for urging said piston means to a position to uncover said port,

said urging means also serving to diminish the force .applied to said piston, and

means for delaying the movement of said piston to said position to uncover said port while permitting rapid movement of said piston to a position covering said port. l

11. A hydraulic jar apparatus comprising:

an upper mandrel member slidably received within a lower mandrel member,

a housing member slida'bly positioned over said mandrel members,

means forming a fluid chamber between said mandrel members and said `housing member,

means extending from said lower mandrel for dividing said chamber into upper and lower portions,

means in said extending means for providing a fluid communication port between said upper and lower portions,

movable piston means positioned in said upper portion, said piston having a depending portion for'covering said port,

means for transmitting a large lforce applied to said upper mandrel to said housing,

means responsive to said force for urging said piston means to a position to uncover said port,

said urging means also serving to diminish the force applied to said pist-on,

means for delaying the movement of said piston to said position to uncover said port while permitting rapid movement of said piston to a position covering said port, and

hammer and anvil means formed on said lower mandrel and housing and positioned to engage one another with impact in response to said piston having moved to a position to uncover said port.

12. A well tool including:

members movable between longitudinal expanded and contracted positions,

said members defining a hydraulic system for delaying movement of said members between said positions in at least one direction and including rst and second chambers adapted to receive a fluid,

said members lbeing arranged to place a fluid in said first chamber in compression and thereby prevent such movement,

valve means for placing said first and second chambers in fluid communciation,

means in said second chamber for operating said valve means after fluid in said rst chamber is in compression for a predetermined period of time, said operating means including a piston and cylinder with hydraulic metering means for restricting travel of said piston in said cylinder for a length of travel and a predetermined period of time, and

spring means lfor moving said piston in said cylinder over the length of travel whereby upon compression of fluid in said first chamber, said spring means moves said piston over the length lof travel for the time before said valve means are opened.

References Cited by the Examiner UNITED STATES PATENTS 2,172,480 9/1939 Osmun 175-297 2,309,872 2/1943 Shaffer et al. 175--297 2,621,024 12/1952 Koppl et al. 175-297 2,678,805 5/1954 Sutliif 175-297 CHARLES E. OCONNELL, Primary Examiner.

I. A. LEPPINK, Assistant Examiner. 

1. A WELL JAR FOR USE IN A WELL BORE COMPRISING; TELESCOPICALLY ARRANGED MEMBERS, A TUBULAR HOUSING SLIDABLY POSITIONED OVER SAID TELESCOPING MEMBERS, MEANS ARRANGED BETWEEN SAID HOUSING AND ONE OF SAID MEMBERS FOR RELEASABLY HOLDING SAID HOUSING FROM SUBSTANTIAL LONGITUDINAL MOVEMENT RELATIVE TO SAID ONE MEMBER, MEANS ARRANGED BETWEEN THE OTHER OF SAID MEMBERS AND SAID HOUSING FOR TRANSMITTING A LARGE UPWARDLY DIRECTED FORCE APPLIED TO SAID HOUSING, AND OTHER MEMBER TO SAID HOUSING, AND MEANS RESPONSIVE TO A MUCH LESSOR FORCE GENERATED BY SAID LARGE FORCE FOR RELEASING SAID HOLDING MEANS AFTER A TIME DELAY TO PERMIT RELATIVE MOVEMENT BETWEEN SAID HOUSING AND SAID ONE MEMBER. 